Power-plant installation



April 2o 1926. 1,581,866

O. T. POST POWER PLANT INSlfALLu'lIONl Filed July '7, 1924 Otto T. PcgtBay //Wo/L fw? H LS ttOPr-xgy Patented pr. 20, 1926.

UNITED STATES PATENT. OFFICE. y

oTro fr.'l Postr, or CHARLOTTENBUEG, GERMANY, AssmNon 'ro ALLGEMEINEELEK- rnrcrrllms-GESELLSCHAET, or BERLIN, GERMANY.

POWER-PLANT INSTALLATION.

Application filed July 7,

To all whom, t may concern.'

Be it known that I, O'rro T. P'os'r, a citizen of Germany, residing atCharlottenburg, Germany, have invented certain new and usefulImprovements in Power-Plant Installations,` of which the following is aspecification.

The" present invention relates to power plant installations employingboth high pressure and low pressure elastic fluid prime movers,'and moreparticularly it relates to such power plant installations wherein thc yexhaust of one or more of the high pressure prime movers is utilized asmotive fluid in one or more of the low pressure, prime movers. n,

The object of the present invention is to provide an improvedarrangement and means .in a' power plant installation of the above 'typefor more advantageously-utilizing in a low pressure prime mover theexhaust elastic Vfluid 4from a high pressure prime mover, whilerendering the two prime movers mutually independent in operation.

'InV similarv power plant installations heretofore, the mutualdependency of two prime movers, which operate in seriesrela-tion on acommon stream of motive fluid, has been avoided to a limited extent byproviding an auxiliary supply source of suitable pressure, such as aseparate boiler directly connected With the low pressure' prime mover,along with'the exhaust conduit of the high pressure prime mover, so thatwith a decrease in the supply from the high pressure prime mover, therequirements of the lower pressure prime mover could be met by drawing4upon the auxiliary source.

4'This arrangement does not, howevenprovide for utilizing increases intheamount 'of motive Huid supp-lied by the high pressure prime moverover that required by the low pressure prime mover. Furthermore, thisarrangement depends upon the heat ex- V change betweenthe superheatedelastic fluid from the auxiliary supply source and the low temperatureexhaust elastic fluidto superheat the latter as the two fluids passthrough the low pressure prime mover, This is obviously less eicient asa. method for superheating the exhaust elastic uid than thewell knownmethod of superheating within a gas heated superheater interposedbetween the prime movers. 1 4

In accordance with the presentinvention,

-with a steam turbine 1924. Serial No. 724,735.

means are provided not only for rendering the low pressure prime moverindependently operable but .also for rendering the high pressure primemover independently operable, So that either prime mover may carry avariable load without influencing the opersov ation of the oth er. Inaddition, means are provided for obtaining the desired vsuperheating ofthe exhaust; from the high presa steam turbine power plantinstallationembodying the invention.

Referring tothe drawing, 2 is a high pressure steam turbine and 3 is alow pressure steam turbine connected together by a shaft .coupling 4.Mounted on an. extension 5 of the shaft of the low pressure turbine isan electric generator 6 which furnishes a common load for the twoturbines, although it Should be understood that this is merely by wayvof example and that the turbines may, if desired, be connected each toa separa-te and dii'erent generator or other form of load.

The high pressure turbine 2 is provided with an inlet at 7 and anexhaust outlet at 8. The inlet 7 is connected with a steam chamber 9 ofa high pressure boiler 10 by a high pressure supply conduit 11 and theexhaust outlet 8 is connected with a steam chamber 12 of a low pressureboiler 13 by an exhaust conduit 14.

The low pressure turbine 3 is provided with an inlet at 15 and anexhaust outlet at 16. The inlet 15 is connected with the steam chamber12 of the low pressure boiler 13 by a low pressure supply conduit 17.The exhaust outlet 16 may be connected to any suitable receiving orcondensing means (not shown). Between the turbine inlet 15 and the steamchamber 12, a superheater 18 is inserted in the supply conduit 17. Thesuperheater is shown in the present example as being a simple verticalcoil formed in the conduit 17, although it may be of any suitable form.As will be readily appreciated, the arrangement is such'that the lowpressure boiler 13 and the superlieater 18 are inserted in theconnection between the exhaust outlet 8 of the high pressure turbine andthe inlet 15 of the low pressure turbine.

The boilers illustrated are substantially similar in construction andrepresent any suitable high and low pressure boilers. They are of thehorizontal drum type having a fire box or combustion chamber 19 at oneend and a fire tube 2O extending therefrom longitudinally of the boiler.The fire box is provided with a grate 21 on which the fuel, indicated at22, is burned. The space above the grate communicates with the tire.tube and is providedwith a fuel ldoor 23 at the front of the boiler. Thespace below the grate is provided with an air inlet opening 24 and adraft controlling damper 25 at the front of the boiler and is separatedfrom the Afire tube 2O by a wall 26 which supports the inner end of thegrate.

The fire box and lire tube are located below the water level, which isindicated at 27, and are thus ina position to effectively heat andvaporize the water. The water level is such that a liberal vapor orsteam -storage space 28A is provided above it, especiallyun the lowpressure boiler 13 for reasons which will be hereinafter explained. Thesteam chambers 9 and 12 hereinbefore mentioned are in communication withand form part of their respective storage spaces 28.

The boilers are mounted m a masonry set- -ting or foundation structure29, of which the floor level is indicated at 30. Below this level afluey passage 31 is formed in said structure for receiving the productsof combustion from the fire tubes of the boilers, a

vertical extension passage 32 forming a connection with the lire tube ofthe high pressure boiler 10, and a similar vertical extension'passage 33forminga connection with the fire'tube of the low pressure boiler 13.

The extension passage 32is controlled by a damper plate 34 which isarranged to slide vertically, in a slot 35 in the floor 30 of thefoundation structure into and out of the flue passage 31. It is shown inthe normal or raised position, providing free communication betweenthefire tube of the high pressure boiler and the flue passage 31.

The extension passage 33 is controlled by a damper plate 36 pivoted at37 to swing vertically over an opening 38 between said extension passageand the flue passage. This damper plate is gravity closed and is raisedto the normal open position shown, bya pull-chain 39 which is connectedat its outer edge and passes vertically upward there- .Of said lowpressure boiler.

from through an opening 40 in the foundation structure to an idler wheel41. Erom the idler wheel it may be extended to any desired control point(not shown). A

The fire tube 20 of the low pressure coller is provided with a by-pass42 which leads from a point adjacent the fire box 19 directly into theflue passage 31. The by-pass is pro vided with a sliding'da1nper-'43which lies at right angles theretoin a slot 44 in the foundationstructure. The damper is Inovable into orout of the. normal closedposition shown, by a handle 45 which protrudes beneath the boiler front.

At the rear of the low pressure boiler 13, a chamber 4G is formed in thefoundation of the flue passage 31. rl`he superheater 13 is locatedwithin this chamber on a perl forated support. 47. A vertical baillewall 43, .which joins the bottom wall and terminates short of the topwall of the chamber, is located closely adjacent to the superheater andserves to direct the flue gases upwardly through the perforated supportand about the super-heater. The support 47 and balile wall 48 are formedintegral with the niasonry foundation. At the opposite side of thebaille wall, au outlet opening 49 is provided in the outer wall of thechamber frf'rn which the flue gases may pass to atmosphere through anysuitable means such as the usual and well known stack or chimney (notshown). 1`he normal direction of flow of theflue gases from the fireboxes 19 to the outlet 49 is indicated by suitably placed arrows.

The normal operation of the installation is as follows Assu'ming thatthe steam re- -quirement of the low pressure turbine is doing work inthe turbine 2, the exhaust lll) steam is conducted by the exhaustconduit 14 to the steam chamber 12 of the low pressure boiler 13 whereit is mixed with the low pressure steam in the storage space 28 Theexhaust steam from the high pressure turbine is partially reheated inmixing with the steam generated in the low pressure boiler and passesalong with the generated steam by way of the low pressure supply conduit1.7 throughthe superheatcr 18 to the low pressure turbine 3 where itsupplements said generated steam in doing further work. The arrangementis such that the exhaust steam from the high pressure turbine issuperheated nell above the saturation point before being utilized in thelow pressure turbine. the superheating being accon'iplished for the mostpart inthe superhater 18 which is located in a position to be travtionof steam in the low pressure boiler may be cheeked by opening theslidingdamper `43 and closing the damper plate 36 over opening 38 sothat the .lire tube 2O of the .low pressure boiler is cut off andthetluegases discharged through the by-pass 42. The heat `in said flue gases isthen utilized only in the superheater `18.

The steamy storage space 28 of the 'low pressure 4boiler is designed tobe relatively arge so that its capacity will be sullicientto meet theusual operating ditlerences between the quantity of steam supplied bythe,

high pressure turbine and the demand for steam by the low pressureturbine. The low pressure boiler thus forms between the high pressureturbine and the low pressure tur# bine, a liexible coupling or storagemeans in thigh additional low, pressure steam may be generated whenrequired.

In case the operatingr conditions are such that the steam requirement ofthe lmv pressure turbineis so low that the .lonT pressure boiler is notrequired for the generation of steam, the fire may be Withdrawn and bothdampers 43 and 36 may be closed, thus isolating the boiler from the lue.passage 31. Under this condition of operation, which may be consideredunusual, the low pressure boiler operates as a storage tank as before,

i y and the superheater is supplied With heating gases only by the highpressure boiler.

It should be understood that the damper plate 36 of the loW pressureboiler is used not only in the closed or open positions as hereinbefoi'edescribed. in connection with the operation, but also -in variousintermediate. positions to control the combustion rate in conjunctionwith the draft controlL ling damper 25 of said low pressure boiler, asis well understood in connection with the operation of any boiler.Likewise they slid'- ing damper 43 may bevmoved to such positionsthatvarious.-quantities of the combustion gas may be `bypassed directly tothe flue to control the generation of steam in said low pressure boiler.In connection with the operation of the high pressure boileiylt), thecombustion is controlled by the damper plate 3ft and the. draft door Tofurther illustrate the operating flexibility of the arrangement asprovided in` accordance with the invention, a condition of operationwill be assumed under which it is desirable or necessary' to remove thehigh pressure boiler 10 and high pressure turbine from service whereby,in the present example, the low pressure turbine Q alone will drire thegenerator G.

Under this condition of operation the fire is withdrawn from the highpressure boiler 2 and damper plate 34 is lowered to cut off said boilerfrom the fiue passage 31. The, high pressure turbine. 2 may remainconnected with the .high and low pressure boilers as shown, or be cutoff therefrom by any desired means such as valves. In the presentexample, the high pressure turbine 2 Vand boiler 10 are merely subjected`throughout to the low pressure of the low pressure boiler 13 and as nooutlet is provided inthe high pressure boiler@ 10, or high pressuresupply conduit 11, no flow of steam will take place in said highpressure turbine.

The low pressure boiler 13 then supplies the low pressure turbine 3 withsteam and the superheater V18 with heating flue gases as if it were a.complete installation entirely separate from the high pressure turbineand boiler. The damper plate 36 and draft door 25 are opened inaccordance with the de.-

mands upon the boiler to provide-the desired draft conditions and thedamper 43 is moved to close the by-p'ass 42.

From "the foregoing description of the present 4embodiment of theinvention, it will be seen that a power plant installation is providedin which a lower pressure prime --mover is arranged to receive theexhaust elastic fluid from a higher pressure prime mover through theintermediary of an auxiliary elastic .fluid supplyA means `which rendersthe installationliexible in operation and the prime movers mutuallyindependent,

in conjunction with means for superheating the supply to the lowpressure prime mover under all conditions of operation'. It willbereadily appreciated by oneskilled in the art that within the scope ofthe invention an additional lower pressure turbine may, if

` deemed advisable in certahifinstallations, be

connected with the exhaust outlet 16 of the low pressure turbine throughmeans duplicating that which connects the present low pressure turbinewith the exhaust outlet of the high pressureturbine.

It should be understood that other high pressure turbinesand boilers maybe connected in parallel with the high pressure turbine and boiler shownand that low pressure turbine and boiler likewise represent any desirednumber of low pressure turbines and boilers connnected in parallel withthem, and it should be understood further that while the invention hasbeen herein described in connection with an illustration representingwhat is now considered to be the best embodiment thereof, saidinven tionmay be carried out by other means.

IVhat I claim as new and desire to secure by Letters Patent of theUnited States, is

1. In a power plant installation, the com` bination with a -highpressure and a low ressure prime mover, of separate elastic fluidgenera-tors for said prime movers, means for conducting the exhaustelastic fluid from the high pressure prime mover to the elastic fluidgenerator of the low pressure prime mover, said generator having arelatively largeelastic fluid storage capacity, and a superheater whichlies in the path ot combustion gases from the generators connectedbetween the said low pressure generator and the low pressure primemover.-

2. In a power plantinstallation having an initial higher pressure primemover and a lower pressure elastic fluid prime mover,

the lower pressure prime mover being con-v nected to receive the exhaustelastic fluid from the higher pressure prime mover, the combination ofan elastic fluid generator connected with the initial higherpressureprime mover, and means interposed in the connection between the higherand lower pressure prime movers 'for rendering said primemovers'ii'iutually independent in oper-Il ation, said means comprising aseparate elastic fluid generator of relatively large storage capacityand a superlieater which lies in the path of combustion gases from the`generators.

:assises 3. In a power plant installation, the coinbination of a highpressure elastic fluid prime mover, a high pressure boiler connectedtherewith, a low pressure elastic [luid lprime mover, a low pressureboiler counected therewith, said low pressure boiler having a relativelylarge elastic fluid storage capacity, a conduit connection between theexhaust outlet of the high pressure 4with, a l`ow pressure elastic fluidturbine, a

low pressure. boiler connected therewith, said low pressure boilerhaving a relatively'large elastic fluidl storage capacity, a superheaterconnected between the low pressure boiler and the low pressure turbine,al conduit connection between the exhaust outlet ot' J(he high pressureturbine and the low pressure boiler, and means for conductingcoinbustion gases from thehigh and low pressure boilers through saidsuperheater, said means including av coiiiinon flue passage l'or theboilers in which the superheater is located. da'i'npers for isolatingeither or both ot' said boilers from the flue passage, a by-pass in thelow pressure boiler, vconnecting the flue passage directly with a pointwithin said boiler adjacent its combustion chamber, and

v a damper controlling said by-pass.

In witness whereof, I have hereunto set my hand this 26th day of June,19:24.

I orro T. Pos'r..

